Ivanchenko A. Degradation Processes in Ceramic Metal Oxide Varistor Structures.

Object - phenomena, responsible for stability and degradational changes of functional parameters in heterogeneous structures. Purpose - determination of the effect of degradation mechanisms on electrical properties of ceramical metaloxide varystoral structures. Methods - mainly standard and intensive regimes of tests on aging were used. Besides experiments of current-voltage and capacitance-voltage characteristics according to classical measuring schemes were carried. The analyses of physical parameters was conducted using generally accepted methods and models. Concrete degradation mechanisms effect on electrical properties of ceramical metaloxide varystory structures, in particular, rechange of surface electronic states, changing of their concentration in the process of termodesorbtion and migration of ions in the volume of crystallites in the electric field were determined. Mathematical models were worked out an possibilities forecasting conduct of varystory products in the exploitation process were shown, in particular, to determine the temperature regimes and their effect on the functional parameter changes. The proposed and approved methods of valuation and control of parameters of varystoral materials which characteries the migration of donor impurity (diffusion coefficient) and the disorder degree of its structure (the radius of correlation of the infinite cluster). Field - prevision of electric properties change of the research of structures during the degradation of the exploitation process, science, technology of the metaloxide varystors production, educational process.